Stout has fewer bubbles than lagers or other carbonated drinks. This is because they contain dissolved nitrogen as well as carbon dioxide. However, Guinness that comes from a can usually has a below par head because of this.

The researchers at UL discovered that adding nitrogen to the drink makes it less acidity and gives it a longer-lasting head and small bubbles which gives it a smooth texture.

Lee told the Irish Examiner "It really came about by chance…We had an intern in last year, Scott, and I gave him a task to do, more with the purpose of showing why Guinness doesn’t get a good head and the science behind it.

"He came back and said if you add this or that it would work, so I obviously went back and checked his results, and was more than surprised.

"You need about 100 million bubbles to get a proper long-lasting head.

"Our model suggested that stout should in fact produce bubbles, and when poured onto cellulose fibres there were bubbles everywhere," he added.

Although no stout producers have contacted them yet the details of their discovery have been published and is likely to have a significant impact on the drinks industry.